How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site. Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask Phil Your Own Question
Phil, Mechanical Engineer
Category: HVAC
Satisfied Customers: 6022
Experience:  Retired HVAC/ Electrical & Boiler contractor. Industrial
Type Your HVAC Question Here...
Phil is online now
A new question is answered every 9 seconds

I need to get my furnace blower motor to stop.

Customer Question

I need to get my furnace blower motor to stop.
Submitted: 2 years ago.
Category: HVAC
Expert:  Phil replied 2 years ago.
Hello.Tell me the brand and model number of the furnace and lot about your technical skill levels so that I will be able to coach you most effectively. Are you familiar with the 'Fan ON/auto' setting on your thermostat? We can go from there.
Customer: replied 2 years ago.
Nordyne m1mb070abw. Yes, I'm familiar with the on/off
Customer: replied 2 years ago.
Also, the trouble indicator light is blinking "Limit Control." I've located 2 of them. One is in the front, easy to get at, and the other is wedged in alongside the blower, hooked to the bottom of the top compartment, very hard to get at. They look the same. But are they? And which one would be the trouble? -if that IS the trouble.
Customer: replied 2 years ago.
And... the blower motor is new as of winter, installed by Consumers Power. It functioned well during winter and has been blowing the AC. The AC cycles properly, maintaining perfect temp but the blower just does not shut off. My thermostat is also new, a Honeywell, it's been good.
Expert:  Phil replied 2 years ago.
Hello again, thanks for the detail.
The FAN switch however does not have an ON and OFF setting... very importantly it is an ON and *AUTO setting... if it is set to Fan Auto the blower will cycle as heat or cooling is called for.
If the FAN switch is set to ON, the fan will run constantly.
This is not to be confused with the System ON and OFF switch, that is a different thing entirely.
This is the most likely problem. 80% chance of that.
The limit switches are there to shut the gas valve off if the furnace over heats, in most cases those particular limits do not control the fan.
Please attach a well focused photo of the wiring diagram glued inside the service panel, you can use the paper clip icon in the tool bar at the top of this dialog box.
Wiring diagrams photo's are best taken so that they almost fill the view screen, must be in good light, and not at an angle.. and of course well focused or they turn into a big gray blob when I blow them up in order to mark them up with coaching instructions.
We can go from there.
Customer: replied 2 years ago.
Will do. And yes, the stat's fan switch is on Auto.
Expert:  Phil replied 2 years ago.
Thanks in that case, one of those limits you mentioned could be open, when that happens on some models, it turns off the gas valve, but also runs the blower until the furnace cuts off. When I get the diagram I will mark it up with trouble shooting directions. .
Customer: replied 2 years ago.
OK, here it is.
Customer: replied 2 years ago.
If this helps .. this problem started as intermittent then in just a couple days stayed on all the time, and, I could shut it off by clicking its circuit breaker on and off and that would turn the blower off til the next AC cylce. But today that trick doesn't even work. When I flip the breaker back on, the blower starts right up.
Expert:  Phil replied 2 years ago.
Hello again, Follow those directions, let me know how it goes, *do not leave the furnace unattended with either of the test jumpers in place.-----------We are on the honor system here. Please remember to rate my service before you leave today. If you need anything else, just let me know. You can continue asking follow-up questions within your agreed on limit at no additional charge. .
Customer: replied 2 years ago.
OK. Thanks. I will try this. I see my $28 payment has already been submitted to my bank account. Thanks again.
Expert:  Phil replied 2 years ago.
Hello again, I am a customer here just as you are, except that I answer questions, if you have questions contact JA at the phone number on your question page or link that they have provided for the purpose.Let me know how it goes. we can proceed from there. .